Well, it looks like the newest version of Molekel uses both Open
Babel and Qt for the interface:
http://bioinformatics.org/molekel/wiki/Main/HomePage
Since Molekel is designed for visualizing surfaces, they have a nice
gallery, which is worth considering. I’m going to contact them about
getting some of the bits integrated back into Open Babel. It would
also be great if we could get some of these bits integrated into
Avogadro:
http://bioinformatics.org/molekel/wiki/Main/Gallery
Cheers,
-Geoff